Rotary pump



T. W. NICHOLS ROTARY PUMP `lune 21, 1932.

Filed Nov. 15, 1931 2 Sheets-Sheet 2 0 mm MM, RE T wmm, mW/ V Y NME ORHw IT Patented June 21, 1932 UNITED STATES i f f 1,864,458

THOMAS WINTER NICHOLS, 'OF "LONDON-ENGLAND :ROTARY PUMP" *i Applicationled November 13, 1931, Serial N'o.

This invention relates to improvements in rotary pumps.

In my United States Patent N o. 1,802,527 I have described an improvedform of construction of a rotary pump of the type in which the rotor isin mesh with a revoluble ring of teeth there being interposed betweenthe rotor and the ring a crescent shaped block, the features of theconstruction being that the rotor has paddle-like teeth formed on orattached to a web of a sleeve forming the hub of the rotor, fixedbearing bushes being arranged between the bottoms of these paddleliketeeth of the rotor and said sleeve, and the ring being formed of twosimilar sized annular members connected by bars which constitute theteeth of the ring meshing with the teeth of the rotor. The pump isprovided with th-e usual inlet and outlet at the respective ends of thecasing and if the pump is to be used for heavy oils an additional inletmay be provided in the form of a lateral inlet passing through the sidewalls of the casing and having openings adjacent the side of the rotor.

My present invention relates to improvements in pumps of the abovedescribed or similar type; and the object of my improvement is first toprovide an improved arrangement of the inlet and outlet ports in orderto allow the pump to be run at very high spe-eds without damage to therotor by the presence of dirt or foreign matter in the substance beingpumped, and second to provide means whereby a thin ilm of the water orother liquid being pumped is formed between the ring and the casing thislm operating as a cushion resisting any tendency of lateral movement orde-central rotation of the ring when revolving at high speeds therebypreventing scoring of the rotary parts by contact with the casing orcrescent shaped block and consequent rapid wear thereof.

I attain these objects by the mechanism illustrated in the accompanyingdrawings in which Fig. 1 is a vertical longitudinal section of theimproved pump, and

Fig. 2 a transverse section thereof on line 2 2 of Fig. 1.

574,882; an'a 'in Great' Britain october 24, 1930;'

Fig. 3 is V'a detail'view bein'gla sectionon' line 3-8 of Fig.Hooking-in-the-"direction of the arrow. A v

Figjll is a partialsection 'o'n-lineBA-BA of Fig. 2 and a full sectiononlineA-t oflFigfS, 55

looking in the direction of the arrow.r

Referring'to Fig. l1 in thepresen't-improved' construction the ring u''instead of being'directly open tolthem'ain inlet-of the pump) casing bas in the construction of my vsaid United 60 States patentisenclosedon'the inlet 'side by a continuation o of the topandfbottomcircularly curved casing 'wallsd within which the ringarotates so that -except for vthe ymain outlet f the ring is enclosedand'rotateswith- 66 in a cylindrical wall.`

yFrom the main inlet ba series of inlet channels g are formed in eachside cover h 'ofthe casing and arebrought around so as to lead intotheinterior of the pump 'on each side" of Zuv andl within the'ring', theinlet here being Ein" the form of one largeinlet port Z1 in the -lateralcasingwall one von each side ofthe rotor and these inlet ports areextended along one side of each bush g1 by recessing saidfbushes.

lThese recesses j are 'formed in each fixed bearing vbush g1 for therotorandpreferably to. an extent reaching tothe central lweb [c of therotor as shown Vby dotted linesin Fig.

2 and in full lines in Figs. 3 and 4 so that' the 30 shown in Figs. 3and 4. Between the rotor Z 85' and the ring a there is provided thecrescent al which is stationary.

The main outlet f communicates with the periphery of the ring a and ofthe rotor Z 9 0 and in addition a port n is provided on each side of themain outlet these being connected by symmetrical channels nl in the sidecovers of the machine with the lateral faces of the bearing bushes thesebeing recessed on each 0.6

side of the web of the rotor as at o so that each channel is incommunication with the bottoms of the teeth m of the rotor on each sideof and to preferably the full length of the bottoms of the teeth of therotor on each 190 side of said web as shown in dotted lines in Fig. 2and in full lines in Figs. 3 and 4.

To maintain a ilm of the liquid being pumped between the outer diameterof the ring and the casing, the front edge of each tooth of the ring isbevelled or radiused tangentially as at p, to allow the liquid to beforced over the teeth into small retaining grooves g, which preferablyrun the entire width of each tooth and partly into the annular membersof the ring, as shown at fr-in Fig. 2. These grooves may be bevelled orY radiused tangentially on the leading or both edges of the teeth. Alsowhen liquids containing solid substances are to be pumped the web 7c atpoints between each of the teeth may be bevelled onl each side asindicated in Fig. 1 at s.

It is to be remarked that with theV internal ports arranged ashereinbefore described the ring is automatically balanced againstdelivery pressure which allows the pump to be run at very high speedswithout undue wear and further the provision of the recesses ando in thebearing bushes allows any particles of hard foreign matter in the liquidbeing pumped to pass through the pump without injuring or clogging thesame.

The pump can be arranged zontally or vertically. A

What I claim as my invention and desire to secure by Letters Patent ofthe United States is l. In a rotary pump of the character described thecombination of a shaft,a rotor on said shaft having a hub, a web andteeth carried by said web, a casing having inlet and outlet ports facingsaid rotor in the axial direction of the pump, a ring cooperating withsaid rotor, a crescent between the rotor and the ring, and fixed bearingbushes for said shaft having flanges engaging between said hub and saidteeth and having arcuate recesses at their rims facing said inlet andoutlet ports. Y

2. A. rotor according to claim l, wherein the arcuateprecesses extendinto said bushes up to the hub of the rotor.

' THOMAS WINTER NICHOLS.

to work hori-

